using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using TeamUp.Modules.OrgBoard.Domain;
using TeamUp.Modules.OrgBoard.Persistence;
using TeamUp.SharedKernel.Ai;
using TeamUp.SharedKernel.Auditing;

namespace TeamUp.Modules.OrgBoard.Runtime;

/// <summary>
/// The single V1 event trigger: a task hitting <c>done</c> emits a handoff that creates a QA task
/// (with provenance) for the team's QA AI seat and dispatches a run — the boundary is a pipe, not
/// a gate; the QA agent then acts per its OWN autonomy. Guardrails: QA/Review tasks never
/// re-trigger (no self-cascade), and a task hands off at most once (the duplicate check is the
/// V1 rate limit). The richer event mesh is Phase 1+.
/// </summary>
internal sealed class QaHandoffTrigger(
    OrgBoardDbContext db,
    IAgentDispatcher dispatcher,
    IAuditLog audit,
    TimeProvider clock,
    ILogger<QaHandoffTrigger> logger)
{
    private const string QaSkillKey = "test-plan-generation";

    public async Task OnTaskDoneAsync(WorkItem item, Guid actorMemberId, CancellationToken cancellationToken = default)
    {
        // No self-cascade: QA's own output never wakes QA again.
        if (item.Type is WorkItemType.Test or WorkItemType.Review)
        {
            return;
        }

        // At most one handoff per task.
        if (await db.WorkItems.AnyAsync(w => w.ParentId == item.Id && w.Type == WorkItemType.Test, cancellationToken))
        {
            return;
        }

        // The receiving seat: an AI seat on this team equipped with the QA skill.
        var seat = await (
            from s in db.Seats
            join a in db.Agents on s.Id equals a.SeatId
            where s.TeamId == item.TeamId && s.State == SeatState.Ai && a.SkillKeys.Contains(QaSkillKey)
            orderby s.CreatedAtUtc
            select s).FirstOrDefaultAsync(cancellationToken);
        if (seat is null)
        {
            return; // no QA AI seat — nothing to hand off to
        }

        var now = clock.GetUtcNow();
        var qaTask = new WorkItem(
            item.TeamId,
            "QA: " + item.Title,
            "Handoff: \"" + item.Title + "\" hit done. Draft the test plan.",
            WorkItemType.Test,
            actorMemberId,
            now,
            parentId: item.Id);
        if (seat.AgentId is { } agentId)
        {
            qaTask.AssignToAgent(agentId, now);
        }

        db.WorkItems.Add(qaTask);
        await db.SaveChangesAsync(cancellationToken);

        var runId = await dispatcher.DispatchAsync(seat.Id, qaTask.Id, cancellationToken);
        await audit.WriteAsync(
            new AuditEvent("handoff.triggered", "WorkItem", qaTask.Id, actorMemberId,
                $"\"{item.Title}\" done → QA run {runId}"),
            cancellationToken);
        logger.LogInformation(
            "PO→QA handoff: task {TaskId} done → QA task {QaTaskId}, run {RunId}.", item.Id, qaTask.Id, runId);
    }
}